Featured Research

from universities, journals, and other organizations

Potential Vaccine Developed For Deadly Leishmaniasis Disease

Date:

April 22, 2006

Source:

American Chemical Society

Summary:

Researchers have developed a potential vaccine for visceral leishmaniasis, a deadly parasitic disease that kills about 60,000 people each year. It is a fundamentally new leishmaniasis "candidate" vaccine made from a synthetic carbohydrate and the empty shells of influenza viruses. The technology points the way to potential new vaccines for other diseases, including cancer.

Share This

Development of a fundamentally new "candidate," or potential, vaccine for visceral leishmaniasis (LEASH-ma-NIGH-a-sis), a parasitic disease that kills about 60,000 people annually, is reported in the current issue of ACS Chemical Biology. Spread by the bite of infected female sand flies, visceral leishmaniasis infects about 500,000 people annually, with the majority of cases occurring in India, Bangladesh, Nepal, Sudan and Brazil.

Related Articles

Despite a major research thrust by the World Health Organization (WHO), no effective vaccine exists for the visceral, or internal, form of leishmaniasis. A milder form of leishmaniasis, which infects the skin, was reported among American military personnel during Operation Desert Storm and other conflicts in the region.

Peter H. Seeberger, Ph.D., of the Laboratory for Organic Chemistry at the Swiss Federal Institute of Technology (ETH) in Zurich headed the research group. It also included researchers from the Swiss Tropical Institute in Basel and Pevion Inc., a biotech company focusing on virosomal delivery systems. The group reported their findings in ACS Chemical Biology, one of 34 peer-reviewed journals published by the American Chemical Society, the world's largest scientific society.

Several leishmaniasis candidate vaccines are in various stages of development. Seeberger's group, however, reported development of a unique two-part preparation. It is among a new genre of carbohydrate-based vaccines stirring excitement in medical circles. Carbohydrates are chemical compounds that include sugar and are made from units linked together like beads on a chain.

"This is the first and only carbohydrate vaccine candidate against this disease," Seeberger stated. "This candidate vaccine brings something new to the table and may be of use not only in humans but also for pet vaccines. Dogs get leishmaniasis, particularly in Southern Europe and a vaccine is urgently needed there, as well."

Carbohydrate vaccines already are used in everyday medicine, including vaccines to immunize against meningitis and other bacterial infections, mainly in small children in the United States. Those vaccines use carbohydrates isolated from the actual bacteria responsible for the diseases. The carbohydrates act as antigens, which stimulate the immune system to deploy a protective shield against disease.

"Right now there is a major push to utilize synthetic carbohydrates as antigens in order to control the purity and composition and avoid possible contamination," Seeberger explained. His own group, together with a biotech company -- Ancora Pharmaceuticals in Medford, Mass. -- is working on one such malaria vaccine that is in late-stage preclinical trials. Other candidate vaccines against anthrax and tuberculosis are at an earlier stage of development.

One major drawback with carbohydrate vaccines is the difficulty in getting them to produce a strong immune response. Vaccine manufacturers achieve this by adding a booster substance -- an adjuvant. The standard existing adjuvant, alum, has limitations. Potential alternative adjuvants are toxic, expensive or have other problems.

The delivery vehicle is an influenza virosome -- the empty envelope of the influenza virus. These flu virus shells contain none of the infectious genetic material in full-fledges flu viruses. The virosome also acts as an "adjuvant," boosting the immune response of the candidate vaccine. The antigen is a synthetic carbohydrate similar to substances on the surface of the leishmaniasis bacteria.

With laboratory studies showing that the candidate vaccine produces a strong protective action against leishmaniasis, Seeberger's group is moving on to the next step toward a leishmaniasis vaccine -- tests in animals.

"To date, carbohydrates have not been used on this delivery platform," Seeberger said. "Therefore, this is a proof-of-principle study that will be applicable to many carbohydrate antigens of importance in other diseases as well," he said. Seeberger cited both infectious and parasitic diseases and vaccines against cancer.

WHO assigned a high priority to development of a leishmaniasis vaccine because of the huge human toll and the lack of any effective treatment. The most common drugs used to treat leishmaniasis have serious side effects and are expensive.

Symptoms of visceral leishmaniasis include fever, weight loss, and abnormalities of the liver and spleen.

More From ScienceDaily

More Health & Medicine News

Featured Research

Mar. 3, 2015 — Adults over the age of 30 only catch flu about twice a decade, a new study suggests. So, while it may feel like more, flu-like illness can be caused by many pathogens, making it difficult to assess ... full story

Mar. 3, 2015 — No significant change in home habits of smokers have been observed in the aftermath of a ban on smoking in public spaces, researchers report. Greater inspiration to kick the habit likely comes from ... full story

Mar. 3, 2015 — Heart function has been associated with the development of dementia and Alzheimer's disease through a new study. Participants with decreased heart function, measured by cardiac index, were two to ... full story

Mar. 3, 2015 — Children of recently separated or divorced families are likelier to drink sugar-sweetened beverages than children in families where the parents are married, putting them at higher risk for obesity ... full story

Mar. 3, 2015 — Gastric bypass and similar stomach-shrinking surgeries are a popular option for obese patients looking to lose weight or treat type 2 diabetes. While the surgeries have been linked to a decreased ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — Twice as many children born to mothers who took antibiotics during pregnancy were diagnosed with asthma by age 3 than children born to mothers who didn’t take prenatal antibiotics, a new study has ... full story

Mar. 3, 2015 — Although sedatives are often administered before surgery, a randomized trial finds that among patients undergoing elective surgery under general anesthesia, receiving the sedative lorazepam before ... full story

Mar. 3, 2015 — Pediatric otolaryngologists and surgeons are concerned with parents getting the wrong message regarding the safety/desirability of letting babies and young children eat peanuts to prevent them from ... full story

Featured Videos

Mom Triumphs Over Tragedy, Helps Other Families

AP (Mar. 3, 2015) — After her son, Dax, died from a rare form of leukemia, Julie Locke decided to give back to the doctors at St. Jude Children&apos;s Research Hospital who tried to save his life. She raised $1.6M to help other patients and their families. (March 3)
Video provided by AP

Looted and Leaking, South Sudan's Oil Wells Pose Health Risk

AFP (Mar. 3, 2015) — Thick black puddles and a looted, leaking ruin are all that remain of the Thar Jath oil treatment facility, once a crucial part of South Sudan&apos;s mainstay industry. Duration: 01:13
Video provided by AFP

Woman Convicted of Poisoning Son

AP (Mar. 3, 2015) — A woman who blogged for years about her son&apos;s constant health woes was convicted Monday of poisoning him to death by force-feeding heavy concentrations of sodium through his stomach tube. (March 3)
Video provided by AP

Nov. 17, 2010 — New research examines the limitations of currently available influenza vaccines and offers direction for developing more efficient and reliable strategies to make vaccines to protect against seasonal ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.